Chronic Fatigue Syndrome (CFS) is a major disabling illness of unknown etiology. It directly impacts more than four million Americans. Infectious agents have been highly suspected but none have ever been validated. Obstacles to their discovery have been lack of a broad approach that can both detect the presence of multiple microbes in a single sample and detect novel or variants of microbes. This has been further hampered because more than 99% of all microbes cannot be cultured and may go undetected. In contrast to past limitations, we will use a new approach that can surmount these obstacles. The discovery of potential pathogens in cerebrospinal fluid of CFS would be field-altering in terms of approach to the study of the disease and possible early detection, prevention and treatment. This could be the gateway step to generate new hypotheses and begin investigation into a microbe's causal association and ways to prevent (egg vaccine) or counteract the effects of a microbial pathogen. PUBLIC HEALTH RELEVANCE: Chronic Fatigue Syndrome is the major acquired disease of productive adults. The cause remains unknown. If we can uncover an infectious cause, which is suspected, diagnostics and therapies may be developed to decrease costs and suffering to the individual and the burden on our health care system and economy.